WHAT IS EXCAVATION ?

When the foundation plan for a building has been transferred on the site, by way of setting out, excavation begins. For very big structures like the stadium, or a multi-storey building, the trenches for the column foundation or wall foundation could be mechanically excavated, holes are mechanically bored where bored pile foundation has been recommended. For shallow trenches, excavation is usually manual and it is executed by labourers, using tools such as shovel, spades and picks.

Generally most of the earth from the shallow trenches can be used for back filling the foundation and the little left is spread within the building area to raise the the level of the floor. The earth is therefore deposited just by the sides of the trenches, The sides of the trenches is not left vertical all through.

The first two – thirds of the depth of the trench from the ground level is given some angle of inclination, or sloped during the final dressing and cleaning up of the trench, this is called in technical words battering, and it is very necessary to remove the sharp-edges of the trench which will break off and fall back into the trench when stepped on during the concreting operations.